Bug#1018004: qt6-tools: does not build and link with system litehtml

[Patrick Franz <deltaone@debian.org>]

Hi,

I tried enabling system litehtml by adding liblitehtml-dev as a B-D
(version 0.6 of litehtml supposedly fixes the issue) and litehtml is indeed found by qttools.

However, the build fails because of

In file included from /<<PKGBUILDDIR>>/src/assistant/qlitehtml/src/container_qpainter.cpp:5:
/<<PKGBUILDDIR>>/src/assistant/qlitehtml/src/container_qpainter_p.h:8:10: fatal error: litehtml.h: No such file or directory
    8 | #include <litehtml.h>
      |          ^~~~~~~~~~~~
compilation terminated.

It seems that while system litehtml is now found, /usr/include/litehtml/ is not included by gcc/g++:

[327/632] /usr/lib/ccache/c++ -DQLITEHTML_STATIC_LIBRARY -DQT_CORE_LIB -DQT_GUI_LIB
-DQT_NO_CAST_TO_ASCII -DQT_NO_DEBUG -DQT_NO_JAVA_STYLE_ITERATORS -DQT_RESTRICTED_CAST_FROM_ASCII
-DQT_USE_QSTRINGBUILDER -DQT_WIDGETS_LIB -I/<<PKGBUILDDIR>>/obj-x86_64-linux-gnu/src/assistant/qlitehtml/src/qlitehtml_autogen/include
-I/<<PKGBUILDDIR>>/src/assistant/qlitehtml/src -isystem /usr/include/x86_64-linux-gnu/qt6/QtWidgets -isystem /usr/include/x86_64-linux-gnu/qt6
-isystem /usr/include/x86_64-linux-gnu/qt6/QtCore -isystem /usr/lib/x86_64-linux-gnu/qt6/mkspecs/linux-g++
-isystem /usr/include/x86_64-linux-gnu/qt6/QtGui -g -O2 -ffile-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -Wformat
-Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -fvisibility=hidden -fvisibility-inlines-hidden -w -fPIC -std=c++17
-MD -MT src/assistant/qlitehtml/src/CMakeFiles/qlitehtml.dir/container_qpainter.cpp.o
-MF src/assistant/qlitehtml/src/CMakeFiles/qlitehtml.dir/container_qpainter.cpp.o.d
-o src/assistant/qlitehtml/src/CMakeFiles/qlitehtml.dir/container_qpainter.cpp.o
-c /<<PKGBUILDDIR>>/src/assistant/qlitehtml/src/container_qpainter.cpp


-- 
Med vänliga hälsningar

Patrick Franz